DYSEMBRYOPLASTIC NEUROEPITHELIAL TUMOR
|Contrast-enhanced CT||T1W MR w/Gadolinium||Proton Density MR|
WHO Grade I
Cell of Origin: Histogenesis uncertain. Hypothesized to arise from external granular layer of the cortex.
Synonyms: DNET or DNT
Common Locations: Cortical, temporal lobe
Demographics: May be seen at any age; most common in children and young adults
Clinical Presentation: Partial complex seizures, especially beginning before age 20
Histology: Diagnosis based on presence of: 1) a specific glioneuronal element, consisting of oligodendrocytes in a mucinous matrix in which neurons appear to "float," or 2) glial nodules associated with cortical dysplasia.
Special Stains: Neuronal markers (synaptophysin, neuronal specific enolase) and glial markers (GFAP, S-100) positive. Despite benign behavior, may have high MIB-1 labeling index
Progression: Usually stable, even over long periods.
Radiology: Nodular cortical lesion without edema or mass effect. May have megagyric or multicystic appearance. Occasionally may enhance or contain calcifications. CT may show calvarial remodeling.
Comments: Surgically curable cause of seizures.